The prior art embraces hundreds of different leg exercise devices which basically involve foot plates (often referred to as carriages, foot pads, foot plates, etc.) which reciprocally track along an elongated track. Some of the devices are designed to place strain upon the exercising limps while others are designed to move more freely. For many therapeutic applications such as stroke victims, elder care knee replacements, ACL (anterior cruciate ligament) injuries, a free tracking movement is required initially until the patient strengthens the injuries and is capable of a more stressful movement. Track seated bearings, journals, or rollers, etc. have become common practice in order to provide a more free tracking movement for foot reciprocating devices.
U.S. Pat. No. 4,645,201 to Evans discloses, a cross-country ski simulating machine relying upon horizontally positioned tracks and foot pads equipped with a nylon friction tape to increase exercise resistance upon the foot pad movements. Similarly, U.S. Pat. No. 4,864,121 to Nestegard discloses foot pads equipped with rollers tracking upon rails and a friction creating accessory to create a desired exercising resistance level.
A ski simulating device relying upon foot plates underpinned by rollers seated within guide rails to ease tracking is disclosed in U.S. Pat. No. 5,690,590 to Lo et al. U.S. Pat. No. 4,804,178 to Friedabach discloses another cross-country ski exercising device which relies on rollers which track so as to inhibit transverse movement of the foot plates. U.S. Pat. No. 4,948,121 to Haaheim et al. and U.S. Pat. No. 4,645,201 to Evans disclose rollers slideably engaging along side rails instead of riding upon the guide rails.
It is evident as reflected by the patent literature that the prior art has taken various different approaches to create leg exercising devices primarily designed for the younger and more athletic exercisers. Unfortunately, none of these exercise devices are of a practical or commercially usable form for medical providers requiring specialized treatment and especially those for requiring low stress therapy treatment of the elderly and patients with leg joint injuries. Certain therapy necessities the least possible amount of strain to effectuate early stage joint movement such as applying the appropriate low strain therapy to repair a recently impaired joint as commonly arises with surgically knee joint replacements. A knee replacement patient will typically be subjected to a motor driven reciprocating (a continuous passive motion or CPM) foot slide in which the patient's knee replacement foot is forcibly moved therein shortly after surgery. This knee therapy can be very painful.
There exists a need for a low cost, effective, durable, sanitary and low stress leg therapeutic device which provides the necessary therapeutic efficacy under more effortless conditions. This is exemplified by a long felt need to apply effective therapeutic treatment for a damaged, injured, or surgical joint replacement. Therapeutic treatment as most commonly and currently used by hospitals and clinics to restore normal joint activity to damaged joints has remained virtually unchanged for decades. This is an exemplified by a knee replacement surgery which necessitates knee joint movement without undue stress as soon as possible following knee replacement surgery in order to effectively rehabilitate the artificial knee joint. A wide spread common therapeutic practice following the motorized forced knee movement therapy involves simply placing the patient's knee replacement foot onto a slideable material such as a paper sheet, towel, etc. and sliding the patient's foot backward and forward while the patient is seated. Notwithstanding a long standing need for a more sophisticated, reliable, and effective low stress therapeutic device procurable at a low cost, decades have since past without any substantive change in the available therapeutic rehabilitating devices for surgically related joint replacements and elder care rehabilitation. An alternative to the archaic therapeutic use of sliding paper or cloth upon an ordinary floor would represent a significant change in the standard therapy for knee replacement patients. A low stress therapeutic device adapted to standardize joint movement, the level of force required and avoidance of detrimental damaging stressful movements while also being effective in preventing accidental misuse by the patient would satisfy a long felt need. Although the aforementioned centers upon knee joint replacement therapy, therapeutic knee recover procedures are generally the same for most other knee injuries such as contusions, muscle tears, sprains, ACL repair, torn or partially torn ligaments, joint nerve damage, such as from stroke, other neurological disorders, etc.